PAPERS GIVIXG RUSTS OF NORTH AMERICA. 233 



the spores. Finally these having fallen out Peziza-form cavities 

 are left in the leaf. 



Represented by half of a leaf, nearly 4.5 cm. broad, mounted, 

 which is thickly covered with uredinia, and by an empty packet 

 labelled "/Ecidiimi Pyrolatum LvS in P. rotyndifol Torn" 



The rust is the uredinial stage of Melavipsoropsis Pyrolcc (DC.) 

 Arth. {Chrysomyxa Pyrolcc Rostr.), but was naturally mistaken for 

 an .TIcidium by Schweinitz, as it possesses catenulate spores. The 

 host may have been P. iiliginosa Tow., rather than P. rotundifolia 

 L. The name JEcidiiim (Cccoma) pyrolatum is used by Schweinitz 

 on page 309 in the same work. 



♦2894. 84. C. A. Myricatum, L.v.S., on leaves and especially on petioles of 

 Alyrica cerifcra, communicated to me from New York by my 

 friend Dr. Torrey. 

 C. spots on strongly swollen petioles, dark purple, black where drj-, 

 and out of the spots project the dense pseudoperidia, rather 

 large, widely open, brown, filled with yellowish spores. 



Represented by a mounted specimen, consisting of a terminal 

 portion of stem, 2 cm. long, wath four leaves attached, three being 

 somewhat over 4 cm. long and 18 mm. wide, and with an abundance 

 of fficia on the hyertrophied terminal bud, 2.5 cm. long, and by an 

 original packet containing 3 cm. of stem with four leaves attached 

 but without secia, which is labelled on the inside " ^licidium Alyricae 

 on Myrica cerifera L," and on the otitside " /Ecidium Myricatum 

 LvS in Myr. cerifera Torrey." 



This is the aecial form of Gymnosporangium inyricatum (Schw.) 

 Fromme (G. Ellisii Farl.), as proven by cultures, the telia of which 

 occur on CJiamcecyparis thy aides (L.) B. S. P. The name is changed 

 to ^ciditon (Gcroma) myricatum on page 309 of the same work. 



*2895. 85. C. A. Osmundatum, L.v.S., found on the fronds of Osmunda 

 spectabilis and communicated by Torrey, but in drying so de- 

 stroyed, that it is not possible correctly to describe it : the species 

 nevertheless evidently distinct: spores ferruginous. 



Represented by a narrowly triangular, lateral part of frond, 2.5 

 cm. long, blackish purple, mounted, and by an empty packet labelled 

 "yEcid? Osmundatum in O. spectab Torrey." Schweinitz used the 



